How a Healthy Heart Works

The heart is a muscular organ about the size of a fist, whose job is to pump blood throughout the entire body. The heart has two sides, right and left, each with two chambers: an upper chamber (atrium) and a lower chamber (ventricle). These four chambers work together in a constant cycle to circulate blood in order to keep the body functioning:

The right atrium receives oxygen-depleted blood from the body and sends it to the right ventricle.

The right ventricle then sends the oxygen-depleted blood to the lungs to absorb more oxygen.

The left atrium brings oxygen-rich blood from the lungs into the left ventricle.

The left ventricle then sends the oxygen-rich blood out to the rest of the body through the largest blood vessel in the body, the aorta.

The circulated blood eventually returns to the right atrium and the cycle continues.